html{
    width: 100%;
    height: 100%;
}
body{
    background-image: url(../image/2.jpg);
    width: 50%;
    height: 30%;
    background-position: center;
    background-repeat: repeat-x;
}
form{
    text-align: center;
    background-color: white;
    width: 300px;
    height: 200px;
    margin: 100px auto;
    padding-top: 20px;
    padding-bottom: 20px;
    border: 1px solid #ddd;
    border-radius: 10px;
}